1. Field of the Invention
The present invention relates to high density recording media such as optical discs, and in particular, blu-ray read-only discs.
2. Description of the Related Art
Optical discs that are capable of storing large amounts of high-quality video and audio data, have been available on the market. The digital versatile disc (DVD) is one example of such an optical disc. Recently, DVD players and DVD recorders have been available on the market and have become one of the most popular consumer electronic products.
Subtitle data that is to be displayed on screen as characters or logo during playback of video data (e.g., a movie) is generally recorded on a DVD in the bitmapped format. While the main video data recorded on the DVD is reproduced, the bitmap-formatted subtitle data is read out from the DVD and output to an external display device such as a TV after a series of signal processing steps so that the bitmap subtitle is displayed on the screen of the external device. In this way, a user can watch subtitles or logo on the screen of a TV during playback of a DVD title.
Recently, the standardization of new higher density optical discs; for example, blu-ray read-only disc (BD-ROM) has been under development. An effective method of reproducing the subtitles recorded on a BD-ROM in a various ways has not been established.